Fuel tank cap capable of capturing harmful vapors

Abstract

A fuel tank cap includes a casing; a main chamber disposed in the casing; a vapor vent channel disposed in the casing and communicating with the main chamber; annular partition walls disposed in the main chamber and configured to divide the main chamber into troughs, each partition wall including a cut so that the troughs are capable of communicating with each other via the cut; and activated carbon filled in the troughs. The vapor vent channel includes the cuts and the troughs. The activated carbon captures fuel vapors and absorbs VOCs in the fuel vapors when the fuel vapors pass through the vapor vent channel. The invention eliminates the low efficiency problem of capturing the harmful VOCs of the fuel vapors by the conventional activated carbon canister.

What is claimed is: 
     
       1. A fuel tank cap comprising:
 a casing; 
 a main chamber disposed in the casing; 
 a vapor vent channel disposed in the casing and communicating with the main chamber; 
 a plurality of annular partition walls disposed in the main chamber and configured to divide the main chamber into a plurality of troughs, each partition wall including a cut so that the troughs are capable of communicating with each other via the cut; and 
 activated carbon filled in the troughs; 
 wherein the vapor vent channel is comprised of the cuts and the troughs; and 
 wherein the activated carbon is configured to capture fuel vapors and absorb volatile organic compounds (VOCs) in the fuel vapors when the fuel vapors pass through the vapor vent channel. 
 
     
     
       2. The fuel tank cap of  claim 1 , wherein the casing is disposed on an opening of a fuel tank. 
     
     
       3. The fuel tank cap of  claim 2 , wherein the troughs formed by the partition walls are concentric. 
     
     
       4. The fuel tank cap of  claim 2 , wherein the cuts are spaced apart and alternate. 
     
     
       5. The fuel tank cap of  claim 4 , wherein the cuts are aligned. 
     
     
       6. The fuel tank cap of  claim 3 , further comprising a passageway formed through a center of the main chamber, and a through hole formed above the outermost trough, and wherein the partition walls and the troughs are concentric about the passageway. 
     
     
       7. The fuel tank cap of  claim 6 , wherein the vapor vent channel further comprises a passageway and a through hole both communicating with the cuts and the troughs. 
     
     
       8. The fuel tank cap of  claim 6 , wherein the passageway, the cuts, and the through hole are aligned. 
     
     
       9. The fuel tank cap of  claim 1 , wherein the casing is disposed on an opening of a fuel tank, further comprising a head space formed on an upper portion of the fuel tank above a surface of gas filled in the fuel tank, the head space being configured to communicate with the atmosphere via the vapor vent channel. 
     
     
       10. The fuel tank cap of  claim 9 , wherein the troughs formed by the partition walls are concentric. 
     
     
       11. The fuel tank cap of  claim 9 , wherein the cuts are spaced apart and alternate. 
     
     
       12. The fuel tank cap of  claim 11 , wherein the cuts are aligned. 
     
     
       13. The fuel tank cap of  claim 10 , further comprising a passageway formed through a center of the main chamber, and a through hole formed above the outermost trough, and wherein the partition walls and the troughs are concentric about the passageway. 
     
     
       14. The fuel tank cap of  claim 13 , wherein n the vapor vent channel further comprises a passageway and a through hole both communicating with the cuts and the troughs. 
     
     
       15. The fuel tank cap of  claim 13 , wherein the passageway, the cuts, and the through hole are aligned.